Contact insertion and removal tool

ABSTRACT

A tool for installing and removing contacts in an electrical connector that includes an insert having continuous openings between the forward and rearward ends, each of the openings receiving a contact which is retained between a rearwardly facing shoulder in each opening and integral resilient fingers on the insert, which incline forwardly and inwardly from the circumferential wall of the opening to engage the rearward contact shoulder. The openings for the contacts include tapering surfaces which contract the longitudinally split insertion and removal tool so that it can enter a smaller portion of the opening adjacent the spring fingers as the contact is installed and removed, allowing the tool to be more readily manufactured in smaller sizes with a relatively wide longitudinal slot.

[ July 23, 1974 CONTACT INSERTION AND REMOVAL TOOL [75] Inventor: Kenneth M. Clark, Beaumont, Calif.

[73] Assignee: The Deutsch Company Electronic Components Division, Banning, Calif.

22 Filed: Apr. 4, 1973 21 Appl. No.: 347,849

Related US. Application Data [60] Division of Ser. No. 167,317, July 29, 1971, Pat. No. 3,727,172, which is a continuation-in-part of Ser. No. 83,782, Oct. 26, 1970, abandoned.

[52] US. Cl. 29/203 H [51] Int. Cl H01! 43/00 [58] Field of Search..... 29/203 R, 203 HT, 203 HC,

[56] References Cited UNITED STATES PATENTS 3,110,093 11/1963 Johnson ..29/203H 6/1967 Blight et al. 29/203 H 5/1968 Lutz et al 29/203 H Primary Examiner-Thomas H. Eager Attorney, Agent, or Firm-Richard F. Carr [5 7 ABSTRACT A tool for installing and removing contacts in an electrical connector that includes an insert having continuous openings between the forward and rearward ends, each of the openings receiving a contact which is retained between a rearwardly facing shoulder in each opening and integral resilient fingers on the insert, which incline forwardly and inwardly from the circumferential wall of the opening to engage the rearward contact shoulder. The openings for the contacts include tapering surfaces which contract the longitudinally split insertion and removal tool so that it can enter a smaller portion of the opening adjacent the spring fingers as the contact is installed and removed, allowing the tool to be more readily manufactured in smaller sizes with a relatively wide longitudinal slot.

7 Claims, 21 Drawing Figures PAIENTEB SHEET R [if 7 1 CONTACT INSERTION AND REMOVAL TOOL REFERENCE TO RELATED APPLICATIONS This is a division of my copending patent application Ser. No. 167,317, filed July 29, 1971, US. Pat. No. 3,727,172 for Electrical Connector, which is a continuation-in-part of application Ser. No. 83,782, filed Oct. 26, 1970, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention:

This invention relates to tools for installation and removal of contacts of electrical connectors.

2. Description of Prior Art:

Some connectors provide for rear insertion and release of the electrical contacts, a desirable feature facilitating the assembly and servicing of the connector, In these connectors, each contact opening includes a rearwardly facing shoulder. There is, .in addition, a metal retaining clip that fits within the opening, having a split outer sleeve portion received between shoulders defined by a circumferential recess in the wall of the opening, while spring fingers incline forwardly and inwardly from the sleeve portion of the retainer clip. The contact includes an annular enlargement that defines forwardly and rearwardly facing shoulders. The contact is held in the insert of the connector by positioning its forwardly facing shoulder adjacent the rearwardly facing shoulder of the insert and the rearward shoulder of the contact against the ends of the spring fingers of the retaining clip. US. Pat. No. 3,158,424 provides an illustration of this contact retention system.

The necessity for utilizing a separate retainer clip'for each contact adds considerably to the number of parts incorporated in the connector. This increases the expense of the connector as well as the required assembly time. The possibility is always present of an improper installation of a retainer clip (such as positioning it backwards), which will prevent it from correctly retaining the contact. The retainer clips also are fragile and very difficult to handle, particularly when used for connectors of small sizes.

In the past, it was proposed to use integral fingers on the dielectric insert to engage the rearward shoulder of the contact, instead of providing a separate metal retaining clip. This design had an insert that wasin two sections bonded together. The connection of the insert sections was made around the periphery of the insert assembly, while interiorly the rearward radial face of the forward insert element was spaced from the forward face of the rearward insert element. This left an open cavity extending the entire interior transverse dimension of the insert unit. Thus, there was a connection between the adjacent contact openings, and the openings were not continuous from front to rear, but interrupted by the cavity. The integral retention fingers projected forwardly from the forward face of the rearward insert element into the interior cavity, stopping short of the rearward face of the forward insert section. This provided the means for holding the contacts in place, with the fingers engaging the rearward contact shoulders, and the rearward face of the forward insert engaging the forward contact shoulders.

The design had certain disadvantages and was not successful commercially. The open cavity within the insert meant that the danger existed that a contact could become misaligned and cocked so that it engaged the adjacent contact to result in a short circuit. Also, a probe or other tool inserted into the connector could move from one contact opening to the adjacent one through the open cavity space, raising further risk of bending or damaging the contacts or misaligning them so that they would not mate properly or could result in a short circuit. Any moisture that found its way into the insert could travel to all of the contact openings rather than being confined to only one as where the contact openings are separated. Furthermore, the inserts of these connectors were made of nylon, which absorbed moisture and lost its strength when exposed to water, and could not withstand elevated temperatures.

Particularly in the design of a relatively small connector with integral plastic fingers, a severe problem arises in making the plastic fingers adequately strong to resist the rearward forces imposed on the contact without buckling and breaking. The retention fingers are- Smaller connector sizes also have created problems in the manufacture of the tools used for insertion and removal of the contacts. These tools conventionally have been split tubular members of plastic material having ends adapted to engage the rearward contact shoulder, as described in US. Pat. No. 3,110,093. It is difficult to mold these tools to a tubular form when the diameter is reduced sufficiently to allow the tool to make proper engagement with contactsof the smaller sizes.

SUMMARY OF THE INVENTION The present invention provides an improved tool for installation and removal of contacts in an electrical connector which overcomes the difficulties outlined above. With the insert of the plug and of the receptacle, which is made of a moistureand temperature-resistant plastic, are integral resilient fingers in each of the contact openings. The forward ends of the fingers are made thicker than the bases of the fingers, and provided with radial edges to engage the contact shoulders. The finger ends also include inner surfaces that are cylindrical segments to complementarily engage the barrels of the contacts. This stabilizes the ends of the fingers to increase their column strength. The larger cross-sectional area at the finger ends provided greater strength and load-carrying capacity both in bending and in shear. The thinner base portions of the fingers have requisite flexibility to allow contact insertion and removal without suffering damage.

Each contact opening includes a rearward portion of relatively large diameter, which connects through an inwardly tapering part to a forward portion of smaller diameter adjacent where the fingers project inwardly. Thispermits the removal tool to be made with a rela tively wide slot and an end portion having an exterior diameter sufficient only to enter the rearward portion of the opening in the insert. lnwardly, the tool includes removal of the contact. Upon removal, the tool engages the fingers forwardly of their connecting points to that there is a finite portion of each finger that is allowed to bend immediately to avoid breakage. For the installation tool, the end part may be relieved circumferentially so that not all the fingers will be engaged by the tool. This insures engagement of the contact shoulder by at least one finger so that the contact will be held in place when the tool is removed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an electrical connector made in accordance with this invention;

FIG. 2 is an exploded perspective view of certain portions of the connector, including in particular the parts used for coupling the plug and receptacle;

FIG. 3 is an enlarged longitudinal sectional view of the connector in the mated position;

FIG. 4 is an exploded perspective view, partially broken away, of the plug insert and shell;

FIG. 5 is a transverse sectional view taken along line 55 of FIG. 3; p

FIG. 6 is a transverse sectional view taken along line 66 of FIG. 3;

FIG. 7 is a fragmentary sectional view taken along line 77 of FIG. 5;

FIG. 8 is a fragmentary enlarged perspective view of one portion of the plug insert assembly, illustrating the contact retention fingers;

FIG. 9 is a fragmentary transverse sectional view taken along line 9-9 of FIG. 3;

FIG. 10 is an enlarged fragmentary view illustrating the details of the finger shape and its engagement with the contact;

FIG. 11 is a fragmentary longitudinal sectional viewing showing the retention finger spaced from the contact shoulder when the contact is shifted forwardly;

the coupling ring, showing one of the bayonet grooves;

FIG. 15 is an enlarged fragmentary sectional view taken along line l515 of FIG. 3, illustrating the engagement of the spring tab on the snap ring and the forward end of the receptacle shell;

FIG. 16 is a perspective view of the contact insertion and removal tool;

FIG. 17 is an enlarged fragmentary longitudinal sectional view showing the tool of FIG. 16 as it is introduced into a cavity in the insert for contact removal;

FIG. 18 is a view similar to FIG. 17, but with the tool pushed all the. way into the cavity for freeing the contact retention fingers from the rearward contact shoulder;

FIG. 19 is a perspective view illustrating a modified form of the contact insertion tool;

FIG. 20 is an enlarged fragmentary longitudinal sectional view illustrating the operation of the insertion tool of FIG. 19; and

FIG. 21 is a transverse sectional view taken on line 2l-2l of FIG. 20.

DESCRIPTION OF THE PREFERRED EMBODIMENT Illustrated in the drawing is a multiple pin and socket connector that includes a plug 9 and a receptacle 10. The general arrangement for retaining the contacts is the same in the plug and receptacle. In the embodiment illustrated, the pin contacts are in the plug and the socket contacts in the receptacle, although this may be reversed if desired. The plug 9 includes a plug shell 11, which is a generally tubular metal member of circular cross section. Within the shell 11 is an insert assembly 12 that serves to retain and hold a plurality of pin contacts 13. The insert assembly 12 includes disks 14 and 15 of a substantially rigid plastic. A suitable material for these members, because of its strength and temperature resistance, is a polyarylsulfone marketed under the trademark Astrel 360 plastic by Chemical Division, 3M Company, 3M Center, St. Paul, Minn. The disks 14 and 15 are suitably bonded together at their mating radial faces. At the forward endof the insert assembly 12 is bonded a gasket disk 16of a resilient elastomeric material, such as silicone rubber.

The insert assembly 12 is retained in the plug shell 11 by means of interengaging castellati'ons on the insert assembly and the plug shell. For this purpose, there are circumferentially extending lugs 18 that project outwardly from the periphery of the rearward disk 15, as seen in FIG. 4. In the embodiment illustrated, there are five of the lugs 18. The circumferential surface 20 from which the lugs 18 project is ssubstantially complementary to the inner surface 21 of the plug shell 11. The slots 22 are made sufficiently'wide to permit the insert circumferential slots 27. This positions the forward 7 assembly 12 to be introduced into the plug shell 11 by being slid inwardly from the forward end 23 of the plug shell, with the lugs 18 passing through the slots 22. The insert assembly 12 is moved into the plug shell until the rearward radial edges 25 of the lugs 18 are brought into engagement with an annular shoulder 26 at the rearward portion of the plug shell.

Circumferential slots 27 are formed at the rearward portion of the inner surface 21 of the plug shell 11, and are of widths substantially equal to the widths of the lugs 18. This provides circumferentially extending shoulders 28 spaced opposite from the annular shoulder 26 of the plug shell. The shoulders 26 and 28 are spaced apart a distance corresponding to the dimensions of the lugs 18 longitudinally of the insert assembly 12. This allows the insert assembly 12 to be rotated after the rearward edges 25 of the lugs have been brought into engagement with the annular shoulder 26. The rotation of the insert assembly brings the lugs 18 in back of the circumferential shoulders 28 and into the edges 29 of the lugs adjacent the circumferential shoulders 28 so thatthe radial shoulders 26 and 28 of the plug shell 11 hold the insert assembly 12 against longitudinal movement relative to the plug shell.

One of the lugs 18 may include a longitudinally forwardly projecting portion 31 having a side edge 32 which is brought into engagement with the side edge 33 of one of the longitudinal slots 22 inthe plug shell for thereby limiting the rotational movement of the insert assembly 12 (see FIGS. 4 and 7). When the forward projection is provided, it assures that the insert assem bly l2 assumes the proper rotational alignment relative to the plug shell. After being properly positioned in the plug shell 11, the insert assembly is locked in place so as to prevent it from being given reverse rotation. This may be accomplished by bonding the insert assembly to the plug shell.

With the insert assembly positioned in this manner, a rearward sealing element 35 made of a resilient elastomer, such as silicone rubber, is bonded to the rearward radial face of the insert assembly and to the rearward portions of the inner circumferential wall 21 of the plug shell.

The pin contacts 13 are received in spaced parallel openings 38 formed in the insert assembly 12. The openings 38 are continuous from the front to the rear of the insert assembly 12, and are separated from each other so that there is no communication from one opening 38 to the other. The connector is designed so that a large number of the pin contacts 13 may be retained in close adjacency, but, for clarity of illustration, only a relatively few such contacts are shown in the drawing.

Each opening 38 includes a relatively wide-diameter portion 39 at the rearward end of the plastic disk which, through a frustoconical portion 40, tapers forwardly to a portion 41 of smaller diameter. A plurality of fingers 42 extends radially inwardly and axially forwardly from the portion 41 of the opening 38 into the continuation 43 of the opening 38 in the member 15. This positions the fingers 42 inwardly and radially opposite the circumferential wall of the portion 43of the opening 38. The fingers 42 are shorter than the section 43 of the opening, so that their forward ends are inward of the forward radial face 44 of the member 15. There are four of the fingers 43 in the example shown, as illustrated in FIG. 8. The fingers 42 are rounded transversely so that collectively they define a generally fructoconical shape with narrow spaces between adjacent fingers. While the plastic member 15 is relatively hard and rigid, the fingers 42 are thin and, therefore, resilient. A radial shoulder is formed by the rearward face 45 of the member 14 where the diameter of the opening decreases at portion 46. In the gasket member 16, the opening has a relatively wide-diameter portion 47 at the rearward end and a smaller-diameter portion 48 at the forward end.

An opening 49 in the rearward sealing member 35 communicates with each of the openings 38.

The pin contacts 13 may be of conventional construction, including hollow, longitudinally elongated barrel portions 50 at their rearward ends, which receive the ends of wires 51 from which the insulation has been stripped. The contact barrels 50 are crimped to the wires 51 to form a mechanical and electrical connection. The wires 51 enter the openings 38 through the openings 49 in the rearward member 35, being engaged by annular sealing beads 52 formed on the circumference of the opening 49. I

Forwardly of the barrel portion 50, each contact 13 includes a part 53 of enlarged diameter which defines forward and rearward shoulders 54 and 55, respectively. Beyond the forward shoulder 54, the contact narrows to a projecting pin portion 56 that is adapted to enter the socket contact. When installed in the opening 38, the forward shoulder 54 of the contact ia adjacent the rearwardly facing shoulder defined by the rearward face 45 of the insert 14, which thereby prevents forward movement of the contact 13.

in this manner, the contact is positioned within the insert assembly and securely retained. With the use of the integral fingers 42, it is unnecessary to provide any auxiliary metal clip for retaining the contact, as in conventional connector construction. This simplifies the manufacture of the connector and lowers its cost. The danger of an improperly installed retainer clip is obviated. With the fingers 43 being entirely received in the section 43 of the opening 38, which locates them rearwardly of the forward face 44 of the disk 15, the bonding together of the inserts 14 and 15 will not adversely affect the fingers. In other words, the fingers are remote from the bond line so that any excess bonding material squeezed out at the joint will not interfere with the movement of the fingers.

As best seen in the enlarged illustration of FIG. 10, the fingers 42 are thicker in cross section at their forward ends than they are at their points of attachment to the insert 15, being tapered gradually in thickness to the rear. Also, each finger has a substantially radial forward end surface 57 which connects at a right angle to an inner end surface 58, which is a cylindrical segment generally complementary to the barrel 50 of the contact 13. When the finger 42 engages the contact 13,

the radial end surface 57 fits behind the rearward shoulder 55 of the contact, while the inner end surface 58 of the finger rests uponthe barrel 50 adjacent the shoulder 55.

The rearward transverse shoulder 55 of the contact 13 does not fall within a radial plane. Instead, it is inclined toward the forward end of the contact. Consequently, the shoulder 55 is undercut, being defined by a frustum of a cone. Desirable results are achieved when the shoulder 55 is inclined at around 12 relative to a radial plane. When the contact '13 is subjected to a force pushing it toward the rear, the undercut shoulder configuration and the inner finger surfaces 58 contribute greatly to the amount of force which can be absorbed before the retention fingers 42 will fail.

With the arrangement of this invention, the fingers 42, loaded as columns, receivev the forces on them near the neutral centers of the columns, minimizing the tendency to buckle. The plastic of the fingers 42, being softer than the metal of the contact 13, becomes distorted where it engages the radially outer portion of the shoulder 55, as illustrated in particular in the enlarged view of FIG. 12. This has the effect of embedding the shoulder in the outer ends of the plastic fingers 42, stabilizing the finger ends. This increases the column strength of the fingers 42 because a column can withstand more loading if its ends are stabilized.

An additional stabilizing effect is realized because of the arcuate inner surfaces 58 of the fingers 42 substantially complementarily engaging the periphery of the barrel 50 of the contact adjacent the base of the shoulder 55. This helps to anchor the free ends of the fingers. The inclined configuration of the shoulder 55 results in a force component on the fingers 42 helping to hold the I surfaces 58 tightly against the circumference of the v barrel 50 to enhance the column stabilizing effect.

The greater wall thickness of the fingers at their outer ends adds to their strength in shear and in bending. The bending strength resists the buckling of the fingers underload.

Another advantage comes from the fact that the inner corner 59 of the finger 42, between the end surface 57 and the inner surface 58, becomes spaced rearwardly from the fillet 60, which necessarily is formed between the shoulder 55 and the barrel 50 when the contact 13 is machined. When there is a straight radial shoulder, the inner corners of the retention fingers will engage the fillet at the base of the shoulder. This deflects the fingers outwardly, thereby tending to cam the fingers out of engagement with the shoulder. The undercut shoulder 55 permits the finger to clear the fillet 60 without requiring a recess in the finger and without sacrifice in the strength of the fingers.

The insert assembly 61 for the receptacle includes a plastic disk 62 that is similar to the member 15. To it is bonded or otherwise suitably secured a forward cover disk 63. The members 62 and 63 also may be made of Astrel 360 plastic. Outwardly projecting lugs 64 on the disk 62 correspond to the lugs 18 on the member 15. The lugs 64 secure the insert assembly 61 to the receptacle shell 65 in the same way that the lugs 18 attach the insert assembly 12 in the plug shell 11. The insert assembly 61 is introduced into the receptacle shell 65 by passing the lugs 64 through axial grooves in the inner surface of the receptacle shell 65, whereupon subsequent rotation of the insert assembly 61 places the lugs 64 between opposed forward and rearward shoulders 66 and 67, respectively, in the receptacle shell. This holds the disk 62 and the cover element 63 within the receptacle.

The socket contacts 68 are retained in continuous separate openings 69 in the insert assembly of the receptacle, positioned against axial rearward movement by integral fingers 70 that project forwardly and inwardly from the insert disk 62. A shoulder 71 on the insert member 63, where the opening 69 reduces in width, is adjacent the forward end of the contact 68 and precludes forward movement of the contact. The fingers 70 are engageable with the rearward edge of the annular enlargement 72 on the socket contact. A wire 73 extends inwardly through an opening 74 in the rearward sealing member 75 of the receptacle 10 for each of the socket contacts 68. The end portions of the wires 73 are stripped of insulation and connected by crimping to the rearward barrel ends 76 of the socket contacts 68. When the forward ends 77 of the socket contacts receive the projecting pin portions 56 of the pin contacts 13 upon the mating of the connector, circuits are completed between the wires 51 and 73.

A rounded annular bead 78 projects outwardly from the forward radial face 79 of the cover disk 63 of the receptacle insert around each of the openings 69. The bead 78 is engaged by the flat forward face'80 of the gasket 16 of the plug 9 when the connector is in the assembled position. Consequently, the bead 78'displaces the resilient material of the gasket 16 and an efficient moisture seal is produced. This type of seal does not rely upon the entry of a projecting part of the resilient elastomer into a recess in the hard plastic of the mating part as in some prior-art designs. Unlike the previous designs, swelling of the gasket 16 from attack of fluids will not appreciably interfere with the mating of the connector so that the axial force required will not vary significantly under those conditions. i

The mechanism for securing the plug and receptacle together in the mated position includes a coupling ring 81 that circumscribes the plug shell 11. The rearward end of the coupling ring includes a radially inwardly extending flange 82 in back of a rearwardly facing shoulder 83 on the plug shell. A snap ring 84 fits in an annular recess 85 in the intermediate portion of the inner circumferential wall of the coupling ring 81. The snap ring 84 is positioned in front of a forwardly facing radial shoulder 86 on the plug shell 11, cooperating with the flange 82 in retaining the coupling ring 81 on the plug shell 11. this allows the coupling ring 81 to rotate relative to the plug shell 11, but relative axial movement is prevented.

Intermediate the snap ring 84 and the flange 82, the coupling ring 81 is provided with three short, arcuate, longitudinally extending recesses 85 in its upper surface 88 (see FIGS. 2 and 5). These recesses are adapted to receive the outer rounded portion 89 of a leaf spring 90. The latter member has normally straight legs 91 terminating in an inwardly bentend 92 which is received within a radial opening 93 in the periphery of the plug shell. This holds the spring to the plug shell 11. Adjacent the legs 91 of the spring 90 are flat chordal surfaces 94 which provide a clearance for permitting flexure of the spring 90.

By this construction, the coupling ring 81 can be rotatedrelative to the plug shell 11, but there is a detent action tending to prevent relative rotation when the portion 89 of the spring 90 enters a recess 87. This retaining force may be overcome by applying adequate torque to the coupling ring to cam the rounded spring portion 89 out of the recess 87, compressing the spring inwardly and allowing the spring portion 89 to slide along the circumferential surface 88 of the. coupling ring intermediate the recesses 87.

Forwardly of the snap ring 84, three bayonet grooves 95 are formed in the inner circumferential surface 88 of the coupling ring. Each groove 95 includes a wide entrance opening 96 at the forward end 97 of the coupling ring, from which there extends an inclined portion 98 of the groove, leading to a circumferential inner part 99 of the groove. The axis of the latter portion of the bayonet groove 95, as best seen in FIGS. 2 and 14, falls entirely within a radial plane as there is no recess for the bayonet pin at the inner end 100 of the groove.

ways in the receptacle shell, assuring the proper rotational alignment of. the plug and receptacle. With the keys in the keyways, the detent spring, when in a 'recess 87 in the coupling ring, positions the coupling ring so that the entrances 96 of the bayonet grooves 95 are aligned with the bayonet pins 102. Therefore, the bayonet pins 102 are brought to the entrances 96 of the bayonet grooves 95 in the coupling ring 81 is a plug and receptacle and advanced axially toward each other. Subsequent rotation of the coupling ring 81 moves the bayonet pins 102 through the inclined portions 98 of the grooves 95 and into the circumferential portions 99, drawing the plug and receptacle into the fully mated position. The coupling ring 81 is turned until the pins 102 are adjacent the inner ends 100 of the grooves 95, which occurs as the outer portion 89 of the spring 90 enters a detent recess 87 in the coupling ring.

A positive stop is provided in one of the bayonet grooves to prevent rotation of the coupling ring 81 past the detent position when the connector is mated. This is accomplished by bending inwardly a small section 106 of the circumferential wall of the coupling ring, presenting an abutment surface 107 in the bayonet groove where it can be contacted by the bayonet pin at the termination of the rotation of the coupling ring 81 (see FIG. 6). This location corresponds to the positioning of the outer portion 89 of the detent spring 90 in a detent receptacle 87. An opening 108 is formed in the wall of the coupling ring adjacent the stop 107, while two additional openings 109 in the coupling ring are spaced 120 from the opening 108. This permits visual exterior inspection of the connector when in the mated position to ascertain whether or not the bayonet pins 102 have moved a sufficient distance into the bayonet grooves 95. When the ends of the pins 102 (which may be painted) can be seen through the openings 108 and 109, it is known that the bayonet pins are in the inner portions of the bayonet slots and that the plug and receptacle are coupled properly.

By this arrangement, the plug and receptacle are advanced axially toward each other the maximum distance when the bayonet pins are adjacent the ends 100 of the grooves95 that receive them. No outward movement occurs as the connection is made, and, when the bayonet pins 102 reach the circumferential portions 99 of the grooves 95, the parts are held in their position of full maximum engagement. Even though subjected to separating force, no relative movement of the plug and receptacle can take place, so that electrical continuity through the contacts is assumed. The bayonet pins 102 are held against the forward sides of the bayonet grooves 95 when separating forces are imposed, while the coupling ring 81 is prevented from movement axially by the engagement of the flange 82 with the rearwardly facing shoulder 83 of the plug shell 11. This provides a solid connection of the parts.

When the connector is in the fully mated position,

. the forward outer periphery of the forward end of the plug shell 11 engages an annular seal 110. The latter member is held in an annular groove 111 in the receptacle shell 65 by bonding.

In some instances, the snap ring 84 may be provided with forwardly projecting tabs 113 that are brought into engagement with the end of the forward portion 101 of the receptacle shell 65 with the connector is mated (see FIG. This puts a desirable tension on the coupled plug and receptacle, eliminating any clearance in the coupling mechanism. This also makes an electrical connection between the plug shell 11 and the receptacle shell 65.

The plug and receptacle are disconnected by reverse rotation of the coupling ring 81 to free the bayonet pins 102 from the bayonet grooves 95. As this is accomplished, the detent spring 90 is forced out of one detent recess 87, and its central part 89 slides along the surface 88 of the coupling ring 81 to the next detent recess 87. In the latter detent position, the bayonet pins 102 have reached the entrances 96 to the grooves and the plug and receptacle may be pulled apart axially.

The integral forwardly inclined fingers 42 in the plug 9 and similar fingers 70 in the receptacle 10, for holding the contact 13 and 68, make possible desirable rear insertion and release of the contacts. In other words, the contact may be both installed and removed from the rearward ends of the plug and receptacle. Installation and removal of the contacts for such connectors ordinarily are accomplished by a tool that includes a split plastic tubular element which fits around the barrel of the contact and engages the rearward contact shoulder as the contact is installed and removed. However, when the contacts are extremely small in size, it is difficult to mold a tubular tool that will be sufficiently small in diameter to engage the contact properly for insertion and removal.

With the present invention, the tool may be constructed as shown in FIGS. 16, 17 and 18, where the end of the tool defines somewhat less than a complete circle, and therefore, is not difficult to form. The contact insertion and removal tool 122 of FIG. 16 is made of a deflectable but generally rigid plastic material. It includes a central part 123 from which extend a portion 124 for contact removal and a portion 125 for contact insertion. The forward portion 126 of the removal end 124 of the tool is arcuate in cross section, but defines less than a complete annulus by having a relatively wide longitudinal slot 127 extending from the outer end 128 of the tool. A shallow beveled surface 129 adjacent the outer end of the tool reduces the transverse dimension and wall thickness at that location. Inwardly of the end 128, the exterior of the tool increases in diameter at a tapered shoulder 130 to a wider portion 131.

The forward portion 126 of the tool 122 has a lateral dimension which permits it to enter into the rearward portion 39 of the opening 38 where the contact 13 is held, as seen in FIG. 17. However, the lateral dimension of the tool inwardly of the tapered shoulder 130 is greater than the diameter of the portion 39 of the opening. Continued axial advancement of the tool into the opening 38, therefore, causes the tapered shouder 130 v to enter the opening section 39, acting as a cam to commanner, it can be moved underneath the fingers 42 as it is advanced axially.

When the forward end of the tool reaches the fingers 42, its reduced width causes it to engage the fingers beyond their points of attachment to the insert 15. The bevel 129 on the tool also gives it a reduced width at its end and helps move the place of engagement between the tool and the fingers forwardly. In other words, the tool does not initially contact the fingers at their bases, but at an intermediate location between their ends. As a result, there is a finite length of each finger rearwardly of where the tool engages it. This provides a length of the finger that can flex immediately as the tool bends it outwardly. Engagement at the base of the finger, however, would leave no adjacent portion to bend and there would be danger of breaking the finger as the tool pried it outwardly.

The wall thickness of the removal portion 124 of the tool at its forward portion 126 is sufficient to deflect the fingers 42 outwardly a distance that will cause them to clear the rearward shoulder 55 of the contact 13. The bevel 129 serves the additional purpose of reducing the tool thickness, so that the fingers will not be bent too far outwardly to cause interference with the wall 43. With the fingers 42 spread apart, the wire 51 and tool 122 are gripped and pulled outwardly, removing the contact 13 from the opening 38.

As a consequence of the convergence of the tool in the opening 38, the tool may be formed to a relatively large lateral dimension and given a wide slot because the wall of the opening in the insert compresses the tool laterally to give it the proper dimension at the forward portion of the opening where the fingers are tobe deflected.

The insertion tool portion 125 is generally similar to the removal tool section 124, having a forward arcuate portion 132 provided with a relatively wide slot 133. In installing a contact, the insertion .tool 125 is fitted around ,the barrel 50 of the contact 13 so that its end 134 engages the rearward shoulder 55 of the contact. The tool is moved into the opening 38 with the contact 13, becoming compressed so that the forward end of the tool enters the smaller-diameter portion 41 of the opening 38 and the width of the slot 133 is diminished. The forward shoulder 54- of the contact cams the resilient fingers 42 outwardly as the contact enters the forward portion of the opening 38, allowing the fingers to slide overthe enlarged portion 53 of the contact and the rearward shoulder 55 to move past the finger ends 57. Then, the insertion tool 125 is pulled outwardly, leaving the contact 13 in its place within the insert of the connector.

The installation and removal for the socket contacts 68 in the receptacle are, of course, the same as described above for thepin contacts in the plug.

In smaller connectors, it becomes difficult to proportion the parts such that the installation portion of the tool will allow the finger ends to overlap the rearward shoulder 55 of the contact when the fingers are pried outwardly by the end of the tool. When the connector v is miniaturized, the rearward shoulder 55 of the contact is quite small in the radial direction. Consequently, the wall thickness of the end of the tool may be very thin if it is to allow the ends of the retention fingers 42 to move inwardly sufficient to engage the shoulder 55 as the tool inserts the contact. Of course, if the fingers 42 do not overlap the shoulder 55, the contact will not be held against rearward movmement, and the tool cannot be removed without pulling the contact outwardly past the retention fingers. On the other hand, if the end wall of the tool is thin enough to allow the fingers 42 to move inwardly an adequate distance to engage the shoulder 55, the tool may have inadequate strength to push the contact into the connector.

The tool 136 shown in FIG. 19 solves this problem, allowing the thickness of the tool to be adequate for contact insertion, at the same time making certain that in all instances the contact will be held in the connector when the insertion tool is removed. The tool 136 of FIG. 19 uses the same removal portion 124 as in the embodiment of FIG. 16. The contact installation portion 137 differs from the prior embodiment primarily by being recessed circumferentially along the opposed edges 138 and 139 of the longitudinal slot at the outer end of the tool. This leaves an end part 140 defined by a cylindrical segment that is less than a semicylinder. Inwardly of the end part 140, the tool portion 137 resembles that of the installation toolportion described above.

Upon inserting a contact, the radial end surface 141 of the tool portion 137 engages the rearward shoulder 55. Because of the large circumferential recess at the end of the tool, only part of the shoulder 55 is engaged by the end surface 141 of the tool, but there is adequate engagement to permit the tool to insert the contact. Also, as a result of the reduced lateral dimension of the end part 140, less than all four retention fingers 42 will be engaged by the end part when the contact has been pushed to its final position (see FIGS. 20 and 21). The fingeror fingers not engaged by the end portion 140 of the tool 137 are free to snap inwardly behind the shoulder 55 to hold the contact in place. The wall thickness of the section 140 may be such that the retention fingers 42 it engages are pried outwardly so, that they clear the shoulder 55. This does not matter, however, because the fingers 42 that already engage the contact shoulder 55 where the end part is cut away hold the contact in the opening as the tool is removed.

' matter what-the relative rotational positions of the fingers and the tool, the end portion 140 may extend through an arc of around when there are four closely spaced retention fingers as in the example shown.

The foregoing detailed description is to be clearly understood as given by way of illustration and example only, the spirit and scope of this invention being limited solely by the appended claims.

I claim:

1. In combination with an electrical connector device having a ,body of dielectric material having a forward end and a rearward end, said body having an opening extending between said forward and rearward ends and spring finger means inclined inwardly and forwardly from the periphery of said opening, and an electrical contact, said contact having a rearwardly facing shoulder for engagement by said finger means, an arrangement for inserting said contact into and removing said contact from said opening comprising a first circumferential surface defining a first portion of said opening having a first diameter, said spring finger means being inclined inwardly and forwardly from a position adjacent said first circumferential surface,

a second circumferential surface defining a second portion of said opening having a second and larger diameter, said second circumferential surface being rearwardly of said first circumferential surface, and a tubular member,

said tubular member being longitudinally split so as to provide opposed spaced longitudinal edges,

said tubular member having an end portion provided with an outer edge adapted to engage said shoulder of said contact,

said end portion having a lateral dimension such that it is adapted to enter said second portion of said opening,

said end portion being of greater lateral dimension than said first diameter,

said end portion being deflectable to compress the lateral dimension of said tubular member to allow said end portion to enter said first portion of the opening,

said tubular member having a second portion of greater lateral dimension than said end portion and said second diameter,

said second portion of said tubular member being movable into said second portion of said opening upon said forward movement of said tubular member,

and a surface interconnecting said end and second portions,

said interconnecting surface being engageable with said body at said second circumferential surface upon movement of said tubular member forwardly relative to said body for thereby so compressing the lateral dimension of said tubular member, said end and second portions of said tubular member and said first and second portions of said opening being proportioned such that said end portion is compressed to a lateral dimension less than that of said first diameter when said second portion of said tubular member is in said second portion of said opening,

whereby said end portion engages said finger means inwardly of the periphery of said openmg.

2. A device as recited in claim 1 in which said outer edge includes a radially inwardly and axially outwardly tapered beveled surface.

3. A device as recited in claim 1 in which said interconnecting surface is substantially frustoconical.

4. In combination with an electrical connector device having a body of dielectric material having a forward end and a rearward end, said body having an opening extending between said forward and rearward ends, a plurality of spring fingers inclined inwardly and forwardly from the periphery of said opening, and an electrical contact, said contact having a rearwardly facing shoulder for engagement by said spring fingers, an arrangement for inserting said contact into said opening comprising a generally tubular member,

said member being longitudinally split so as to provide spaced longitudinal edges, said member having an end portion with an outer end surface adapted to engage said rearwardly facing shoulder for pushing said contact into said opening from said rearward end, said longitudinal edges adjacent said end surface being spaced apart a distance such that upon pushing said contact in said opening said tubular member engages less than all of said spring fingers irrespective of the relative rotational positions of said member and said fingers, whereby the ends of said spring fingers not engaged by said member are free to position themselves behind said rearward shoulder for holding said contact in said opening upon said insertion of said contact by said mem ber.

5. A device as in claim 4 in which said distance said longitudinal edges are spaced apart adjacent said end surface is greater than the spacing between said longitudinal edges inwardly thereof, whereby said longitudinal edges are recessed circumferentially adjacent said end surface.

6. A device as recited in claim Sin which said member where said edges are so recessed is defined by a substantially cylindrical segment which is less than a semicylinder.

7. A device as recited in claim 6 in which said substantially cylinder segment extends through an arc of around 

1. In combination with an electrical connector device having a body of dielectric material having a forward end and a rearward end, said body having an opening extending between said forward and rearward ends and spring finger means inclined inwardly and forwardly from the periphery of said opening, and an electrical contact, said contact having a rearwardly facing shoulder for engagement by said finger means, an arrangement for inserting said contact into and removing said contact from said opening comprising a first circumferential surface defining a first portion of said opening having a first diameter, said spring finger means being inclined inwardly and forwardly from a position adjacent said first circumferential surface, a second circumferential surface defining a second portion of said opening having a second and larger diameter, said second circumferential surface being rearwardly of said first circumferential surface, and a tubular member, said tubular member being longitudinally split so as to provide opposed spaced longitudinal edges, said tubular member having an end portion provided with an outer edge adapted to engage said shoulder of said contact, said end portion having a lateral dimension such that it is adapted to enter said second portion of said opening, said end portion being of greater lateral dimension than said first diameter, said end portion being deflectable to compress the lateral dimension of said tubular member to allow said end portion to enter said first portion of the opening, said tubular member having a second portion of greater lateral dimension than said end portion and said second diameter, said second portion of said tubular member being movable into said second portion of said opening upon said forward movement of said tubular member, and a surface interconnecting said end and second portions, said interconnecting surface being engageable with said body at said second circumferential surface upon movement of said tubular member forwardly relative to said body for thereby so compressing the lateral dimension of said tubular member, said end and second portions of said tubular member and said first and second portions of said opening being proportioned such that said end portion is compressed to a lateral dimension less than that of said first diameter when said second portion of said tubular member is in said second portion of said opening, whereby said end portion engages said finger means inWardly of the periphery of said opening.
 2. A device as recited in claim 1 in which said outer edge includes a radially inwardly and axially outwardly tapered beveled surface.
 3. A device as recited in claim 1 in which said interconnecting surface is substantially frustoconical.
 4. In combination with an electrical connector device having a body of dielectric material having a forward end and a rearward end, said body having an opening extending between said forward and rearward ends, a plurality of spring fingers inclined inwardly and forwardly from the periphery of said opening, and an electrical contact, said contact having a rearwardly facing shoulder for engagement by said spring fingers, an arrangement for inserting said contact into said opening comprising a generally tubular member, said member being longitudinally split so as to provide spaced longitudinal edges, said member having an end portion with an outer end surface adapted to engage said rearwardly facing shoulder for pushing said contact into said opening from said rearward end, said longitudinal edges adjacent said end surface being spaced apart a distance such that upon pushing said contact in said opening said tubular member engages less than all of said spring fingers irrespective of the relative rotational positions of said member and said fingers, whereby the ends of said spring fingers not engaged by said member are free to position themselves behind said rearward shoulder for holding said contact in said opening upon said insertion of said contact by said member.
 5. A device as in claim 4 in which said distance said longitudinal edges are spaced apart adjacent said end surface is greater than the spacing between said longitudinal edges inwardly thereof, whereby said longitudinal edges are recessed circumferentially adjacent said end surface.
 6. A device as recited in claim 5 in which said member where said edges are so recessed is defined by a substantially cylindrical segment which is less than a semicylinder.
 7. A device as recited in claim 6 in which said substantially cylinder segment extends through an arc of around 155*. 